This invention relates to water filters and more particularly, to an underwater filtration operator which can be positioned in a water body to filter and disinfect water from the water body for drinking or other purposes. The underwater filtration operator includes a housing having a selected configuration and divided into multiple filtration units which receive water from the water body, each of which filtration units includes at least one filter element or medium for filtering the water. A pump is provided in the housing for pumping the filtered water to a suitable container or dispenser or to a reverse-osmosis filtration unit for further filtration, and a positive electrical charge may be applied to the housing or to an insulated outer screen to neutralize negatively charged impurities flowing through the filter media and improve filtration efficiency.
Treatment processes for filtering surface water have remained virtually unchanged for over half a century. Many surface water treatment plants utilize large settling basins, known as clarifiers, to settle out heavy solids from water prior to fine-screening the water, using rapid sand filters. Some of these treatment plants use a mixing chamber clarifier to separate the heavy solids from the water. Such a mixing chamber clarifier requires the introduction of polymers, lime, alum or other types of media into the water to be treated, which media bind particulate impurities in the water and fall with the bound impurities to the bottom of the mixing chamber. The filtered water, substantially devoid of the larger impurities, is then processed through horizontal sand filters which remove smaller impurities from the water. The sand filters must be periodically backwashed using large quantities of clean water because they repeatedly become clogged with the smaller particles that were not removed from the water during the clarification process. The fewer the particles removed during the clarification process, the more often the backwashing procedure must be repeated.
The foregoing types of surface water treatment plants are associated with many problems due to the nature of their operation. Numerous pumps and an expensive elaborate intake structure must be installed in the water supplies to conduct the water to the plants for treatment. Another problem involves the disposal of solids that are removed from the water. Formerly these solids, along with the chlorine, polymers, lime or other particulate binding media, were pumped back into the pre-filtered water from which they were removed. Due to recent environmental legislation, however, it is no longer lawful to discharge the particulate binding media into the pre-filtered water supply, as these materials are not endemic to the water that is being treated. Another problem associated with these filtration systems is that the polymers or other particle binding media introduced into the filtration system are harmful to certain types of boiler water industrial filtration and equipment which utilizes reverse osmosis. This increases the cost of boiler water for industrial consumers. Furthermore, disinfectant chemicals introduced into the filtered water do not always kill all parasites found in water sources. Furthermore, rapid sand filters cannot remove all of these parasites, some of which remain in the water and present a potentially dangerous health risk. Another problem associated with these surface water treatment plants is the inability to remove harmful chemicals which may contaminate the water supply by agricultural run-off or accidental spills. Accordingly, surface treatment plants can be costly and time-consuming to build and maintain.
A number of different types of filters are known in the art for filtering surface water. Patents of interest in this regard include U.S. Pat. No. 4,606,819, issued Aug. 19, 1986, to Colson; U.S. Pat. No. 4,643,836, issued Feb. 17, 1987, to Schmid; U.S. Pat. No. 4,657,672, issued Apr. 14, 1987, to Allen; U.S. Pat. No. 4,950,393, issued Aug. 21, 1990, to Goettl; U.S. Pat. No. 5,160,039, issued Nov. 3, 1992, to Colburn; U.S. Pat. No. 5,549,828, issued Aug. 27, 1996, to Ehrlich; and U.S. Pat. No. 6,027,639, issued Feb. 22, 2000, to J. Lenhart et al.
An object of this invention is to provide an underwater filtration assembly or operator capable of filtering water from a river, lake, pond or other water body.
Another object of this invention is to provide a self-contained underwater filtration operator which is simple in construction and operation and can be designed to float on the water body.
Yet another object of the invention is to provide an underwater filtration assembly or operator which is charged with electricity to neutralize negatively charged impurities flowing through the filter media in the operator and thereby improve filtration efficiency.
Still another object of this invention is to provide an underwater filtration operator device which includes a filter screen or screens that may be positively charged with electricity, multiple filtration units that may be negatively charged and are provided in the housing for receiving the water, at least one filter element or medium provided in each filtration unit for filtering the water and a pump provided in the housing for pumping the filtered water to a collection container or dispenser, or to a reverse osmosis filtration unit for further treatment.
A still further object of the invention is to provide a method of filtering water in a water body comprising the steps of providing a self-contained underwater filter operator having filter screens, placing the operator in a water body, providing a pump in the operator, optionally providing a positive charge on one or more of the filter screens or the insulated housing and pumping water through the filter and from the filter to an outside storage facility for further treatment.
These and other objects of the invention are provided in an underwater filtration assembly or operator and method of filtering water in a water body, which operator can be suspended in a lake, pond or other water body to filter water from the water body. The underwater filtration operator includes a housing having a selected configuration and enclosing multiple filtration units, each of which units includes at least one filter element or medium for filtering water from the water body. A pump is provided in the housing for receiving the filtered water from the filtration units and pumping the filtered water to a suitable collection facility or dispenser, or to a reverse osmosis filter for further treatment. An insulated outside filter grid or screen or the insulated housing in the operator may be positively charged with electricity to neutralize negatively charged impurities flowing through the filter media with the raw water and enhance the filtration efficiency.